Thank you very much! This helps a lot. I think I am ready to render now. Jon
On Wed, 3 Dec 2003, Matto Marjanovic wrote: > > >I think I've figured it out, but if someone could verify my results, that > >would be great. I think I need to design at 1365x768. Using the > >information from the VCD stills page and other pages I found, I built a > >little aspect ratio converter that, given the number of pixels high and > >wide the destination platform is, and the display aspect ratio, it will > >calculate what width/height you should design at. > > > >If anyone wants to offer comments, that would be great, as dealing with > >the various aspect ratios has me tipping on the edge of insanity. > > Hiya, > > My first instinct is to refer you to http://www.mir.com/DMG/aspect.html > (which I myself am now turning to...). > > width DAR 1024 16/9 16 * 768 4 > -------- = ----- --> ---- = ----- --> SAR = ---------- = - > height SAR 768 SAR 9 * 1024 3 > > So, you're target material has a sample aspect ratio of 4:3 (which > evokes a big retrospective "Duh", because you are taking a standard > 4:3 screen and stretching the pixels by 4:3 to create a 16:9 screen). > > > The options that I can think of: > > 1) Use y4mscaler to do the scaling. This should do it: > > ... | y4mscaler -O size=1024x768 -O sar=4:3 | ... > > You can start with any input and it should scale it to look correct > on that funky screen, but "1365.3-x768" is an ideal source size (with > a 1:1 SAR) if you want to fill the whole screen. > > 2) You are rendering an animation, right? If it is a decent renderer, > you should be able to specify both the frame size and the sample aspect > ratio. This is ideal, because the machine only renders the pixels that > you actually need and you can avoid any post-process scaling. > > > If the screen/stream is going to be interlaced, you will want to avoid any > vertical scaling. If the renderer is classy enough to synthesize an > interlaced output, then (2) should be a viable option, anyhow. (Although, > if this is going through Windows Media Player, I guess interlacing is > probably not anywhere in the equation.) > > > Another thought --- are you saying that the Windows running through this > big wide screen looks widened? I would think that Windows sees the screen > as 1365x768, outputs a 1:1 SAR frame of that size, and a scaler built into > display actually smooshes the pixels together to put it on the glass. > Or does Windows actually produce a non-1:1 SVGA output? I would think > "No way" --- and every display on the market is going to assume that its > *input* is 1:1 pixels, just because nobody understands non-square pixels > anyway. > > If all this is the case... just render at 1365x768 with 1:1 pixels and > you are done. (Phew!) > > -matt m. > ------------------------------------------------------- This SF.net email is sponsored by OSDN's Audience Survey. Help shape OSDN's sites and tell us what you think. Take this five minute survey and you could win a $250 Gift Certificate. http://www.wrgsurveys.com/2003/osdntech03.php?site=8 _______________________________________________ Mjpeg-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/mjpeg-users
